Hello, syzbot found the following issue on: HEAD commit: 47ec5303 Merge git://git.kernel.org/pub/scm/linux/kernel/g.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1083e7ec900000 kernel config: https://syzkaller.appspot.com/x/.config?x=e0c783f658542f35 dashboard link: https://syzkaller.appspot.com/bug?extid=6048aa700d088954b0fc compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11c227dc900000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+6048aa700d088954b0fc@xxxxxxxxxxxxxxxxxxxxxxxxx ------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 3805 at lib/refcount.c:25 refcount_warn_saturate+0x13d/0x1a0 lib/refcount.c:25 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 3805 Comm: krfcommd Not tainted 5.8.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1f0/0x31e lib/dump_stack.c:118 panic+0x264/0x7a0 kernel/panic.c:231 __warn+0x227/0x250 kernel/panic.c:600 report_bug+0x1b1/0x2e0 lib/bug.c:198 handle_bug+0x42/0x80 arch/x86/kernel/traps.c:235 exc_invalid_op+0x16/0x40 arch/x86/kernel/traps.c:255 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536 RIP: 0010:refcount_warn_saturate+0x13d/0x1a0 lib/refcount.c:25 Code: c7 93 1e 15 89 31 c0 e8 71 0c a9 fd 0f 0b eb a3 e8 88 66 d7 fd c6 05 97 4d ed 05 01 48 c7 c7 ca 1e 15 89 31 c0 e8 53 0c a9 fd <0f> 0b eb 85 e8 6a 66 d7 fd c6 05 7a 4d ed 05 01 48 c7 c7 f6 1e 15 RSP: 0018:ffffc90001997b80 EFLAGS: 00010246 RAX: b5077223a4630100 RBX: 0000000000000002 RCX: ffff88809902e380 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: 0000000000000002 R08: ffffffff815dffd9 R09: ffffed1015d262c0 R10: ffffed1015d262c0 R11: 0000000000000000 R12: ffff88808df4b4b8 R13: ffff88808df4b080 R14: 0000000000000000 R15: dffffc0000000000 refcount_add include/linux/refcount.h:205 [inline] refcount_inc include/linux/refcount.h:241 [inline] sock_hold include/net/sock.h:692 [inline] bt_accept_dequeue+0x34e/0x560 net/bluetooth/af_bluetooth.c:206 l2cap_sock_accept+0x21c/0x430 net/bluetooth/l2cap_sock.c:332 kernel_accept+0x143/0x410 net/socket.c:3569 rfcomm_accept_connection net/bluetooth/rfcomm/core.c:1931 [inline] rfcomm_process_sessions+0x1c5/0xc540 net/bluetooth/rfcomm/core.c:1990 rfcomm_run+0x3b5/0x900 net/bluetooth/rfcomm/core.c:2086 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Kernel Offset: disabled Rebooting in 86400 seconds.. --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
